Abstract #0123

Insights Into the Origin of Spontaneous Coherent BOLD Fluctuations in a Resting Rat Brain Under Varied Isoflurane Anesthesia Depth

Xiao Liu^1,2, Xiao-Hong Zhu¹, Yi Zhang¹, Wei Chen^1,2

¹CMRR, Radiology, University of Minnesota, Minneapolis, MN, USA; ²Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA

This study observed the spontaneous coherent BOLD fluctuations in the somatosensory system of isoflurane-anesthetized rats. It was found that both the amplitude and coherence strength of the BOLD fluctuations could be modulated by changing the anesthesia level in the critical range of 1.8% ~ 2.2% isoflurane, and such anesthesia-level-dependent modulation of BOLD fluctuation is very similar to that of CBF fluctuation signal, which has been proven to be tightly coupled with simultaneous-recorded EEG signals. Therefore, the overall results suggest the neural origin of coherent BOLD fluctuations observed in the present study and thus provide an important MRI signal source for mapping resting-state connectivity.